/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.dx.dex.file;

import com.android.dx.util.AnnotatedOutput;
import com.android.dx.util.Hex;

/**
 * Indirect reference to an {@link AnnotationSetItem}.
 */
public final class AnnotationSetRefItem extends OffsettedItem {

	/** the required alignment for instances of this class */
	private static final int ALIGNMENT = 4;

	/** write size of this class, in bytes */
	private static final int WRITE_SIZE = 4;

	/** {@code non-null;} the annotation set to refer to */
	private AnnotationSetItem annotations;

	/**
	 * Constructs an instance.
	 * 
	 * @param annotations
	 *            {@code non-null;} the annotation set to refer to
	 */
	public AnnotationSetRefItem(AnnotationSetItem annotations) {
		super(ALIGNMENT, WRITE_SIZE);

		if (annotations == null) {
			throw new NullPointerException("annotations == null");
		}

		this.annotations = annotations;
	}

	/** {@inheritDoc} */
	@Override
	public ItemType itemType() {
		return ItemType.TYPE_ANNOTATION_SET_REF_ITEM;
	}

	/** {@inheritDoc} */
	public void addContents(DexFile file) {
		MixedItemSection wordData = file.getWordData();

		annotations = wordData.intern(annotations);
	}

	/** {@inheritDoc} */
	@Override
	public String toHuman() {
		return annotations.toHuman();
	}

	/** {@inheritDoc} */
	@Override
	protected void writeTo0(DexFile file, AnnotatedOutput out) {
		int annotationsOff = annotations.getAbsoluteOffset();

		if (out.annotates()) {
			out.annotate(4, "  annotations_off: " + Hex.u4(annotationsOff));
		}

		out.writeInt(annotationsOff);
	}
}
